if you are strength training and i mean purely a powerlifter then i would eat a nutritious meal about 90-120 minutes prior. something like eggs and fruit is a staple
if you are a weight lifter or bodybuilder then absolutely training fasted is perfectly fine. no don't listen to your friend that says to take dextrose, we already get so much sugar there is absolutely no need for that. just hydrate and go.
btw i did something that nobody out there can claim in that i fasted 19 days and weight trained just about everyday during that. i had some of my best workouts of my life. granted i had to make sure i was hydrated and my strength was down, but the workouts were fantastic and adrenaline was off the charts